<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        @keyframes yuan {
            0% {}

            100% {
                transform: rotate(360deg);
            }
        }

        body {
            background-color: rgb(171, 105, 217);
        }

        div {
            width: 200px;
            height: 200px;
            border: 10px solid transparent;
            border-radius: 50%;
        }

        .box1 {
            position: relative;
            margin: 100px auto;
            border-color: rgba(255, 255, 255, .3);

        }

        .box2 {
            position: absolute;
            top: -10px;
            left: -10px;
            border-top-color: #fff;
            animation: yuan 1.5s linear infinite;
        }
    </style>
</head>

<body>
    <div class="box1">
        <div class="box2"></div>
    </div>
</body>

</html>